Non-specific immunosuppressive therapy of man is associated with considerable morbidity. Some regimens may be superior to others. The New Zealand mice offer a convenient model for studying different drug regimens prior to study in patients. Soluble suppressor substances have prolonged life in NZB/NZW mice. Treatment of NZB/NZW mice with Ribavirin, a broad spectrum antiviral drug, has been very effective. Renal deposits of immune complex can be prevented. Such treatment is potentially applicable to humans with SLE. Male sex hormones, testosterone and 5 alpha-dihydrotestosterone (but not Danazol) prolonged life in female NZB/NZW mice. Such treatment was effective even when started after clinical illness and did not require castration for its full effect. However, NZB mice are much less sensitive to androgen administration.